To determine in subjects with Type I DM, whether glycemic control can be acheived at least as effectively with a) an intensive insulin regimen involving pre-meal inhaled insulin plus twice daily subcutaneous NPH insulin as well, and/or b) an intensive subcutaneous insulin regimen involving pre-meal Regular Insulin plus twice daily NPH, given as 4 injections per day. The treatment regimens differ only by the route of delivery of the short acting insulin. This study will examine the toleration and safety of inhaled insulin therapy and its effects after 6 months, if any, on measures of pulmonary function.